#include "base64.h"

bool is_base64(unsigned char c) {
    return (isalnum(c) || (c == '+') || (c == '/'));
}

std::string base64_encode(char const* bytes_to_encode, int in_len) {
    std::string ret;
    int i = 0;
    int j = 0;
    unsigned char char_array_3[3];
    unsigned char char_array_4[4];

    while (in_len--) {
        char_array_3[i++] = *(bytes_to_encode++);
        if (i == 3) {
            char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
            char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
            char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
            char_array_4[3] = char_array_3[2] & 0x3f;

            for(i = 0; (i <4) ; i++){
                ret += base64_chars[char_array_4[i]];
            }
            i = 0;
        }
    }

    if(i){
        for(j = i; j < 3; j++){
            char_array_3[j] = '\0';
        }

        char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
        char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
        char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
        char_array_4[3] = char_array_3[2] & 0x3f;

        for (j = 0; (j < i + 1); j++){
            ret += base64_chars[char_array_4[j]];
        }

        while((i++ < 3)){
            ret += '=';
        }
    }

    return ret;
}

std::string base64_decode(std::string const& encoded_string) {
    int in_len = encoded_string.size();
    int i = 0;
    int j = 0;
    int in_ = 0;
    unsigned char char_array_4[4], char_array_3[3];
    std::string ret;

    while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
        char_array_4[i++] = encoded_string[in_]; in_++;
        if (i ==4) {
            for (i = 0; i <4; i++){
                char_array_4[i] = base64_chars.find(char_array_4[i]);
            }

            char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
            char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
            char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

            for (i = 0; (i < 3); i++){
                ret += char_array_3[i];
            }
            i = 0;
        }
    }

    if (i) {
        for (j = i; j <4; j++){
            char_array_4[j] = 0;
        }

        for (j = 0; j <4; j++){
            char_array_4[j] = base64_chars.find(char_array_4[j]);
        }

        char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
        char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
        char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

        for (j = 0; (j < i - 1); j++){
            ret += char_array_3[j];
        }
    }

    return ret;
}

std::string vectorToString(std::vector<std::string> &v){
    std::stringstream ss;
    unsigned int length = v.size();
    for(unsigned int i=0 ; i<length ; i++){
        ss << base64_encode(v[i].c_str(), v[i].size());
        if(i<length-1){
            ss << std::endl;
        }
    }
    return ss.str();
}

std::vector<std::string> stringToVector(std::string &str){
    std::stringstream ss(str);
    std::vector<std::string> v;
    std::string line;
    while(!ss.eof()){
        getline(ss, line);
        v.push_back(base64_decode(line));
    }
    return v;
}
